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Determination of the Neoproterozoic Shicaogou Syn-collisional Granite in the Eastern Qinling Mountains and Its Geological Implications 被引量:21
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作者 CHENDanling LIULiang +4 位作者 sunyong ZHANGAnda ZHANGChengli LIUXiaoming LUOJinhai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第1期73-82,共10页
The Shicaogou granite has been identified as a magnesian (Fe-number=0.71-0.76), calcic to calc-alkalic (MALI=3.84-5.76) and peraluminous (ASI=1.06-1.13) granite of the syn-collisional S-type, with high SiO2(>71%), ... The Shicaogou granite has been identified as a magnesian (Fe-number=0.71-0.76), calcic to calc-alkalic (MALI=3.84-5.76) and peraluminous (ASI=1.06-1.13) granite of the syn-collisional S-type, with high SiO2(>71%), A12O3 (>13%) and Na2O+K2O (6.28%-7.33%, equal for NaO2 and K2O). Trace element and REE analyses show that the granite is rich in LILE such as of Rb, Sr, Ba and Th, and poor in HFSE like Yb, Y, Zr and Hf. Its Rb/Sr ratio is greater than 1; the contents of Nb and Ta, and the ratio of Nb/Ta as well as the REE geochemical features (e.g. REE abundance, visible fractionation of LREE and HREE and medium to pronounced negative Eu anomalies) are all similar to those of crust-origin, continent-continent syn-collisional granite. Moreover, the granite exhibits almost the same pattern as that of the typical continent-continent syn-collisional granite on the spider diagram and all samples fall within the syn-collisional granite field.The cathodoluminescence (CL) investigations have revealed that the zircon from the Shicaogou granite represents a typical magmatic product characterized by its colorless, transparent and euhedral crystals, and distinct zoning of oscillatory bands. Residual cores of irregular zircon can be found in a few enhedral grains. Trace element studies of the zircon grains, with high contents of P, Y, Hf, Th, U and REE and high ratios of Th/U, obviously positive Ce anomalies and HREE enrichment compared to LREE, also result in the same conclusion.The LA-ICP-MS U-Pb isotopic data from 24 spots of 21 zircon grains demonstrate that 20 spots in the oscillatory zone yield an average weighted 206Pb/238U age of 925±11 Ma, indicating that the Shicaogou granite was formed in the Neoproterozoic. Combined with other Neoproterozoic syn-collisional granites found in the study area, the present geochronological determination can further reveal that collision-amalgamation events could have occurred among some continental blocks in the Qinling orogenic belt during the Neoproterozoic. This in turn provides an accurate chronological constraint on the Neoproterozoic break-up and convergence in the belt. 展开更多
关键词 LA-ICP-MS U-Pb dating ZIRCON syn-collisional S-type granite geological implication Shicaogou eastern Qinling Mountains
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水相和无溶剂体系中生物质基乙酰丙酸制备γ-戊内酯的研究进展
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作者 唐兴 李伟乐 +3 位作者 刘淮 孙勇 曾宪海 林鹿 《精细化工》 EI CAS CSCD 北大核心 2021年第12期2385-2392,共8页
戊内酯(GVL)是一种颇具应用潜力的生物质基平台化合物,可通过乙酰丙酸(LA)催化加氢的方式合成。目前,研究者已针对不同的溶剂体系开发出多种催化剂用于LA选择性加氢还原制备GVL。其中,水相和无溶剂体系中催化LA加氢是绿色经济的GVL合成... 戊内酯(GVL)是一种颇具应用潜力的生物质基平台化合物,可通过乙酰丙酸(LA)催化加氢的方式合成。目前,研究者已针对不同的溶剂体系开发出多种催化剂用于LA选择性加氢还原制备GVL。其中,水相和无溶剂体系中催化LA加氢是绿色经济的GVL合成途径,但上述体系对催化剂的水热稳定性和耐酸稳定性具有非常高的要求。该文着重对近年来在水相和无溶剂体系中催化LA加氢合成GVL的进展进行了归纳总结。此外,还分析了不同催化体系中LA加氢合成GVL的优劣势。最后,对水相和无溶剂体系由LA制备GVL提出了建议。 展开更多
关键词 乙酰丙酸 γ-戊内酯 水相体系 无溶剂催化体系 催化剂
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